Automatic traffic control system



Nov. 17, 1931. R. s. sEEsE 1,832,510

AUTOMAT I C TRAFF IC CONTROL SYSTEM Filed April 26, 1924 3 Sheets-Sheet l Nov. 17, 1931. R. s. sEEsE 1,832,510v

AUTOMATIC TRAFFTC CONTROL SYSTEM Filed April 26, 1924 n 3 Sheets-Sheet 2 n ucmffofo:

95 flagemjleense WWW Nov. 17, 1931.

R. s. sEEsE AUTOMATIC TRAFFIC CONTROL SYSTEM Filed April 26, 1924 3 sheets-.Sheet s @Hommio Patented Nov. 17', 1931 UNITED STATES PATENT OFFICE ROBERT S. SEESE, OF DETROIT, MICHIGAN, ASSIGNOB. T FROST AND SEESE, A COPART- NERSHIP COMPOSED. 0F NORMAN MICHIGAN J'.` FROST AND ROBERT S. SEESE, OF DETROIT,

AUTOMATIC TRAFFIC CONTROL- SYSTEM i i Application led .April 26,

This invention relates to a signal system and more particularly to an automatic traiiic control system. An obj ect of the present invention is to provide a; system which is simple and efficient in ope1'ation,"cheap to construct, install and maintain, and in which the necessity for an electric motor for effecting;

. signal changes is obviated.` A further object is to provide certain other new and useful features in the constructlon, arrangement and y combinationbf elements, all as hereinafter nected in the system is effected, and further consists in the arrangement and connection in the system of devices whereby the several objects are attained,l the invention also con- Sistine` in the combinat' of electrically operated devices, arrangement of circuits and certain other new land useful features, all as hereinafter more fully set forth and particularly pointed out in the appended claims,

reference being had to the accompanying drawings, 1n whlch v Figure 1 is a diagrammatic vievv of a signal system illustrative of the present invention;

Fig. 2 is a diagrammatic view illustrating a modified construction and arrangement of the system shown in Fig. 1

Fig. 3ds a view of a signal or trailic control device of suitable construction for-use in connection with the system, and diagrammaticallv shown inFigs. 1 and 2 for the purpose of illustra-ting an application of the invention, and l Fig. 4 is an enlarged detailfview of a thermostatic relay shown in Fia'. 2.

Traiiic congestion in thel larger cities, and

l to a lesser extent throughout the country has become so great 'that mechanical or electrical means for directing or controlling traffic movement has been quite universally adopted, the devices which automatically operate at predetermined intervals to display certain A Isignals in sequence, have been devised, but 1 such automatlc devices all employ an elec- 1924. Serial N o. 7Q9,284.

tric motor, and acomplicated arrangement of wiring and switches to eiect the desired signal operation. The present invention contemplates securing the desired signal operation through the employment of electrically operated devices which are very simple in construction and which are so arranged and combined as to eiiect the desired result in a l.simple and eflicient manner-and without the use of electric motors or other complicated mechanism which is liable to get out of order.

To control the operation or effect operation at delayed intervals and in certain sequence of certain signals, such as the lighting of a lamp or lamps, or the operation of audible alarms or signals, a thermostatically controlled de- Vi^e or devices are employed, each device being rendered operative by the passage of currentI therethrough, and as an example of a very eiicient device and one which is simple in construction and cheap to manufacture, thermostatic relays of an old and well'known form are indicated as a whole in Fig. 1 by the numerals l, 2, 3 and 4, said relays each comprising a. metal strip formed of two leaves of dissimilar metals riveted or welded together. face to face. so that upon the application of heat to said strip, due to the passage of currentthrough any sliitable resistance, said strip will be deflected or will bend, due to the difference in thel coeicient of expansion ofthe two metals and close a circuit controlled thereby.

The device which is indicated as a whole by the numeral 5, and is diagrammatically illustrated in Fig. 1, comprisesa magnetic relay, the contactarm 6 of which is normally held up or in contact with a contact-7 by a spring f 8a and is pulled down against the action of said spring into contact with a Contact .8, by means of a coil 9. and is held down to maintain such contact. bv a holding` coil 10.

The device indicated diagrammaticallv in Fig. 1 bv the numeral 11 comprises a Dart of the trailic control device shown as a whole in able casing A divided into three compartments B. C and D. the device or lamn 11 being positioned within the compartment Dra similar device or lamp 12 being. positioned within Fi 0r. 3. which control device comprises a suitthe compartment B and the warning device or devices 13 and 14 indicated diagrammatically in Fig. 1, and which, as shown in Fig. 3, is a single lamp 13 located in compartment C, the other Warning device 15 connected in series with said lamp being shown diagrammatically in Fig. 2, and is located in any convenient part ofthe casing.

A simple and conveniently arranged tratiic control device particularly adapted for controlling traflic at intersectingr streets and A which may be mounted upon a suitable pedestal at the street intersection or suspended from an overhead support in the usual manner, is illustrated in Fig. 3, but it will beunderstood that any other construction or arrangement of visible or audible signals may be employed to suit the particular conditions of installation and traic, the present device being shown merely as an aid in explaining the operation of a system embodying the present invention. The control device shown in Fig. 3 is arranged for controlling traffic at street intersections, the 'light 12 being arranged to control north and south traffic by being placed Within the compartment B having in the four Walls thereof snitablelenses,

of which are provided with lenses, which are arranged with the green lenses 18 facing east and west traffic and the red lenses 19, north .and south trailic, so that when the lamp 12 is extinguished and the lamp 11 lighted, green signals Will appear" to east and West traiiic and red signals to north and south traic.

The compartment C is arranged in the casy ing A between the compartments B and D and in this compartment C is the warning lam'p 13 or lamps 13 and 14 which are provided to give a Warning signal indicating that direction in traffic is about to be changed,r and all four Walls of this compartment C are provided With yellow lenses 20 to indicate to both vnorth and south .and east and West trafic, that a change in traiiic right-of-way is about to take place. The length of time which each one of all of the lamps will remain lighted is controlled by a thermostatic relay and the time intervals of lighting the lamps 11 and 12 may be changed at will by providing rheostats 21 and 22 connected in the circuits of the thermostatic relays 1 and 2, as

shown diagrammatically in Fig. 1, each timecontrol rheostat being provided with the usual control or setting knob 23, as shown in Fig. 3, by means of which knobs the rheostats may be adjusted. These rheostats are preferably placed, together with any suitable circuit controlling switch 23a and the several thermostatic relays and other devices connected in -the circuit, Within a separate compartment E in the lower: part ot' the casing A for convenience of installation and op'eration and compactness of assembly, the front Wall of the casing being in the form of a door 24 which may be opened to give access to the several compartments.

As illustrated diagrammatically in Fig. 1, the several thermostatic relays 1, 2, 3 and 4, together with, the magnetic relay 5 and several lamps 11, 12, 13 and 14 are all connected Within suitable circuits to opera-te as follows:

7hen current is flowing in the main or supply circu'it comprising the Wires 25 and 26, lamp 13 is lighted, current fiowing through the wire 25, Wire 27 which is electrically connected to the free end of the bendable blade or strip 28 of the thermostatic relay 1,- through said strip, and through a Wire 29 to lamp 13. From lamp'13 the current flows through Wire 30 which is electrically connected to the free end ofthe bendable strip 31 of the thermostatic relay 3, thence through said strip and Wire 32 leading to lamp 11, through said lamp 11 which is of less resistance than lamp 13 so that it will not light, and from said lamp through Wire 33 which is connected to contact 7 of the magnetic rela 5, from which contact it passes r through t 1e contact arm 6 and wire 34, to the return Wire 26 of the main line. The lighting of this lamp 13 gives the warning signal, indicating that a change in the direction of movement of traiiic is about to take place.

As soon as current begins to pass through strips 28 and 31 of the relays 1 and 3 respectively, these strips commence to bend laterally due to the heating effect of the current, and when strip 31 engages its contact 35 which contact is electrically connected withy the Wire 29 by the Wire 36, the lamp 13 is short circuited and extinguished, and lamp 11 immediately lights, indicating that the Way is clear for east and West traffic. Upon the closing of thermostatic relay 3, movement of strip 28 of relay 1 is accelerated and after an interval predetermined by the setting of the rhcostat 21 which is connectedacross the Wires 25 and 29, partly short circuiting the strip 28, the strip 28 comes into contact with its contact 27 a, completing the circuit from Wires 25 and 27, through contact 27a, wire 37 electrically connectedto said contact and resistance coil 38 connected therein. to electromagnet coil 9 and from said coil by Wire 39 to Wire 34 and return Wire 26 of main circuit. Flow of current through coil 9 energizes said coil, the movable core of which is connected to the contact lever 6, and causes llO a movement of said core which swings said contact lever out of contact with contact 7 and into contact with contact 8 and extinguishes lamp 11, at the same timeflighting the lamp 14 through the connection, wire 25, wire -connected to the free end ofstrip 41 of thermostatic. relay 2, through said strip and wire 42 electrically connecting the iixed end of said stri and the holding coil 10, throughv said coil and wire 43 to lamp 12,

through said lamp and wire 44 to lamp 14,

thelamp 12 being of less resistance than lamp 14 does not light; the return connection being through wires 45 and 46, through the thermostatic strip 47, wire-48 connecting said strip and contact 8, through the arm 6 which is in con-tact with the contact 8, and wire 34 to the return wire 26. This lighting of the 'lamp 14 gives the warning signal to indicate that the direction of tratlic is about to be changed from east and west to north and south.

Strip 28 of relay 1 now gradually cools, breaking contact at 27a and de-energizing coil 9, but as current is still flowing through holding coil 10 due to the closing of the circuit at 8. said coil will operate to hold the arm 6 against contact 8. Current is also passing throughthermostatic strips 41 and 47 which are thereby heated and begin to bend, the strip 47 being the first to come into engagement with its contact due to the time control of the relay 2 by its rheostat 22 connected across the lines 25 and 42 and partly short circuiting the relay 2. The engagement of strip 47 with its contact 49 shortV circuits the lamp 14 `,as the wire 50 leading from said contact is connected to wire 44 and the lamp 12 at once lights, giving the signal that north and south streets are open to traiiic and immediately thereafter movement of strip 41 of relay 2 is accelerated.

, After an interval of time predetermined by the adjustment of the rheostat 22, strip 41 comes into engagement with its contact l51`which is connected by wire 52 with wire` 43, short circuiting, holding coil 10, thereby -releasing contact bar 6 of magnetic relay 5 and breaking contact at 8 and making contact at 7 which breaking at 8 extinguishes the lamp 12. The strip 41 then cools and breaks the circuit at 51, completing the cycle. of operation which is then repeated, again starting with the lighting of lamp 13 to again givethe warning that a change in thedirection of traffic is about to take place.

In Fig. 2 a modified arrangement of circuit and devices therein is shown, but the control of traiic by means of the. display of certain colored lights in certain sequence is substantially the same as above described in connection with the description and operation of the arrangement shown in Fig. y1.

In Fig. 2 an arrangement is shown wherein a single warning light performs the duty of ing arranged to cooperate, one to control they operation of the other.l

The thermostatic controller which is indicated as a whole in Fig. 2 by the numeral 53, comprises two thermostatic strips 54 and 4 55 similar to the several thermostatic strips comprising the relays 1, 2, 3 and 4 of Fig.

1, except that leach strip is provided with a.l

free end portion 56 formed of insulating material and these two strips are set at an inclination to each other with their free ends converging and the insulated end portions in contact and overlapping so that when one strip (as 54) is inl unflexed' condition it will be in engagement with its contact 57 at the lower side of the strip and the other strip 55 will by reason of overlying the end of strip 54 be held against its contact 60 at the upper side thereof and out of contact with its contact 59. lVhen these strips change their positions due to the flexing of strip 54 caused by the heating eiect of current' y shown in Fig. 2, these relays being indicated 'as a whole by the numerals`61 and 62, and

there are also employed four magnetic relays,

eachv indicated as a whole by the numerals 63, 64, and 66, said relays 63 and 64 beingl of the same construction as the magnetic relay 5 of Fig. 1, and the relays 65 and 66 arey also of the same construction, except thatl Ithey do not include the holding coil 10 of relay 5. I

Separately describing each of the several circuits and the sequence and operation of the several devices therein all as diagrammatically shown in Fig. 2:

First operation: Assuming the device 53 to bein the position shown in Fig. 2 and the entire apparatus ready for operation, and assuming that the main supply wire 68 and the main return wire 79 are connected to a suitable source of current supply; operating coil 84 is energized by current iiowing through supply Wire 68, connecting wire 69 to` contact 57, through Wire 67 and resistance 67a connected therein to oneend of coil 84, thence through wire 84a connected to the opposite end of said coil, and to Wire 93 which in turn is connected to the main return wire .79. This flow of current closes relay 63, assisted by the flow vof current through path 68, connection 90 to contact 60 and from contact 60 through Wire 97 and resistance 60a connected therein to one end of the holding coil 88, and from the opposite end of this holding coil to the wire 84 and through wire 93 to the return Wire 79, said coil 88 being thus energized to hold Arelay 63 in closed position.

Second operation: Closing of the relay 63 closes the circuit through lamp 12, the path of current being supply wire 68, connection 69, strip 54, wire 70 connected to the fixed end of the strip, contact arm 71 of relay 63, contact 72 and wire 73 to lamp 12. From said lamp the path'otl currentl is through wire 74,

strip 75 of relay 61, wire 76 to coil 77 of relay v. 65 and from said coil through wire 78 to return wire 79. T he resistance of coil 77 however, is suflicient to prevent lamp 12 from lighting, although sutlicient current will pass through lamp 12 to operate relay 65 which is closed by the coil 77 and suiicient current will also pass at this moment to heat the thermostatic strip 75 and start it to bending toward itsfcontact 80.

Third operation: The closing of relay 65 closes the circuit through the contact arm 81 and contact 82 of said relay and the current now Hows through path 68, wire 83 to lampv 13 and bell 15, and returns through Wire 86 to contact arm 81, then through contact 82 and Wire 87 tothe mail return Wire 7 9. The caution lamp 13 is ther fore lighted and the bell rings, thus indicating to trafic that a change in the direction of trailic is about to take place.

Fourth operation: While the caution lamp 13 and bell 15 are operating, strip 75 coni tinues to move toward its contact 80,'and after an interval of time which is predetermined by the construction of strip 75, contact is made between 75 and 80. This closes a shunt 80a around coil 77 and short circuits this coil, this allowin relay 65 to open by breaking the contact between 81 and 82. The bell 15 and caution lamp 13 then ceases to operate.

Fifth operation: The short circuiting of coil 77 allows suilicient current through lamp 12 to light this lamp, thus signalling to north and south tratlic that the Way is clear, and

blocking east and west traffic.

Sixth operation: From the time of closing the circuit as described in the second operation above, the current passing through lamp 12 and coil 77, also passed through strip 54 ot the thermostatic controller 3, and during that interval the end 56 of strip 54 has been moving away from Contact 57 and toward contact 58. This movement of strip 54 is accelerated by the short circuiting of coil 77 and the lighting of lamp 12. When the insulated end 56 of strip 54 passes the insulated end of of strip in its movement from contact 57 to contact 58, strip 55 drops into engagement with contact 59 and breaks contact at 60. Contact is also made at 58 by strip 54.

Seventh operation: The breaking of contact at releases holding coil 88, and since contact at 57 was previously broken when strip 54 moved out of contact therewith, relay 63 opens, extinguishing lamp 12. Contact is then broken between and 80 due to the cooling of strip 75 of relayA 61.

Eighth operation: At the same time the new contact made at 59 (see sixth operation) causes current to vflow through path 68, 90, 59, Wire 91, resistance 92 therein to coil 89 of relay 64, and from said coil lcurrent flows through the Wire 93 to the return wire 79, thus energizing` coil 89 and closing relay 64 assisted by holding coil 94 which is energized through path 68, 69, contact 58, wire 95 and Y resistance 96 therein to one end of the coil 94,

and from the opposite end of the coil through ywire 93 to return wire 79.

Ninth operation: Closing of relay 64 closes the circuit through a -lamp 11, the current owing through 68` 90, 55, 98, contact arm 99,

contact 100, wire 10,1 to lamp 11 and from saidv lamp through wire 102 to strip 103 of relay 62 and through Wire 104 connected to said strip and 105 to coil 106 of relay 66 and from said coil to Wires 107 and 93 to return wire Y 79. IThe resistance of coil 106 however is suflicient to prevent lamp 11 from lighting, although sufficient current passes through lamp 11 to operate relay 66 which is ,closed by coil 106. Sufficient current also passes at this moment to heat thermostatic strip 103 and start it bending toward its contact 108.

, Tenth operation: The closing of relay 66 brings contact arm 109 into contact with 110, thus completing the circuit from 68 through 83, lamp 13, bell 15, Wire 86,I arm 109, contact 110, Wire 111, and wire 87 to return Wire 7 9. The caution lamp 13 then lights and the bell 1'5 rings, thus indicating to traffic that a change in the direction of traffic is about to take place.

Eleventh operation: While the caution lamp 13 and bell 15 are operatingfa .strip 103 continues to move toward its contact 108, and after a suitable interval, Which is predetermined by t-he construction of strip 103, con tact is made between 103 and 108, thus short oircuiting the operating coil 106 of relay 66, which short circuiting causes contacts 109, 110 to be broken and bell 15 and caution lamp 13 to cease operation.

Twelfth operation The short circuiting of coil 106 'allows suflicient current to flow through lamp 11 to light this lamp and thus y closing the circuit described in the ninth peration above, the current passing through lamp 11 and coil 106 is also passed through strip 55 of the thermostatic controller 53, and'during that time said strip is movingv away from its contact 59 toward its contact 60. This movement is accelerated by the short circuiting of coil 106 and thesequent lighting of lamp 11. When the insulated end 56 of'strip 55 passes the insulated end of strip 54 in its movement between contacts 58 and at the same time strip 55 makes contact at 60.

The cycle of operation is now complete, and the supply of current through supply wire 68 continuing, the cycle of operation will be repeated, starting with the first operation above described.

To retard the length of intervals of north and south traiiic, a rheostat 112 is connected across wires 69 and 70,` which are the wires leading to and from the strip 54 of the thermostatic controller 53, vand thus the flow of current to this strip may be accurately regulated to regulate the heating of the strip,

and therefore the time required to cause it to and make contact at the other.

Similarly, the interval of east and west traic is regulated by5 thermostat 113 connected across wires 90 and 98.

' The interval during which bell 15 and lamp 13 will operate 'is regulated by adjustment of thermostatic relays 61 and 62. Caution inter'- vals preceding ,east and west or north and south traflic may therefore be so regulated as to be of the same or different lengths,

What I claim is 1. A trailic signalling system comprising a i transition signal (13) and a direction signal (11) of less resistance than the transition signal, a current-controlled thermostatic switch (1) having a flexible element (28) connected to said transition signal (13), a second current-controlled thermostatic switch (3) having a flexible element (31) and with its ends connected respectively to saidv signals, fixed contacts (27a, 35) engageable respectively by said flexible elements, the flexible element (28) of the rst switch (1) being connected to the fixed contact (35) of the second switch (3), the flexible element (31) of the second switch (3) being connected to said direction signal (11), a main line (25) connected to the flexible element (28) of the first switch (1)', a return line (33 from the direction signal (11), a magnetic switch xed contact (7) at the end of said line, a pivotally mounted magnetic switch 'lever (6) adapted to engage said xed contact (7 ),means (8a) normally holding said lever in engagement with said contact, another main line`(34-26) connected to said lever, a solenoid 9, a core attached to said lever and entering said solenoid, said A solenoid having one end connected to the fixed contact (27a) of the first named thermostatic switch (1) and the other end to the last named main line (34), another magnetic switch fixed contact (8) engageable by said lever (6), a third current-controlled thermostatic switch (4) having a fixed contact (49) and a flexible element (47), the latter being connected to the 'last named magnetic switch contact (8), another direction signal (12) and another transition signal (14) having a series connection (44) therebetween, said connection being joined to the last named fixed contact (49) the last named direction signal (12) being of less resistance than the last named transition signal (14), a holding coil (10) surrounding said core, a fourth current-controlled thermostatic switch (2) having a flexible element (41) and a fixed contact (5l), the former (41) being connected to the first named main kline (25 and to one end of said holding coil (10%, a line (43) connecting the remaining end of lsaid holding coil (l0) to the last named direction signal (12), the fixed contact (51) of the fourth thermostatic switch" (2) being connected to the line (43) which connects the holding coil (10) to the last named direction signal (12). Y

2. A traffic signalling system as described in claim 1, further characterized by means for regulating the current flowing through the flexible elements (28,- 41) of said first and fourth thermostatic switch (1, 2).

In testimony whereof I afiiX my signature.

ROBERT S. SEESE. 

